A significant logistical and manpower drain on urban combat units is the maintenance of building security once initially secured. Urban battlefields are truly porous, three dimensional environments whereby enemy combatants can infiltrate secured areas via roofs or tunnels among other hidden ingress/egress points. Enemy combatants in a defensive posture have had time to prepare the battlefield for just such action and also have intimate knowledge of the infrastructure of the cityscape on their side.
The experience of the Russians in Chechnya is a classic case in point. Chechen soldiers routinely circumvented the front lines of the operation via tunnels, etc. to appear in the rear of the Russian lines to inflict very heavy casualties. Due to this threat, units leave soldiers behind to guard buildings to maintain security. Consequently, as a fighting force advances, its capabilities are consistently sapped.
Simple, single-point electronic measures that can detect intrusions would significantly mitigate the personnel burden on urban operations units. The ideal would be to have a single system capable of monitoring an entire extended region (e.g. a neighborhood). However, even a single system capable of monitoring a single building is a significant step up. A serious logistical issue when considering such systems is how much infrastructure must be brought along to ‘instrument’ the building. If too rigorous, the equipment/logistics burden can be almost as damaging to the fighting capability as the rear guard requirement.